const fs = require('fs')
const path = require('path')
const zlib = require('zlib')
const rollup = require('rollup')
const uglify = require('uglify-js')

if (!fs.existsSync('dist')) {
  fs.mkdirSync('dist')
}

let builds = require('./config').getAllBuilds()

// filter builds via command line arg
if (process.argv[2]) {
  const filters = process.argv[2].split(',')
  builds = builds.filter(b => {
    return filters.some(f => b.dest.indexOf(f) > -1)
  })
}

build(builds)

function build(builds) {
  let built = 0
  const total = builds.length
  const next = () => {
    buildEntry(builds[built])
      .then(() => {
        built++
        if (built < total) {
          next()
        }
      })
      .catch(logError)
  }

  next()
}

function buildEntry(config) {
  const isProd = /min\.js$/.test(config.dest)
  const output = config.output
  const { file, banner } = output
  return rollup
    .rollup(config)
    .then(bundle => bundle.generate(output))
    .then(({ output: [{ code }] }) => {
      if (isProd) {
        const minified =
          (banner ? banner + '\n' : '') +
          uglify.minify(code, {
            fromString: true,
            output: {
              screw_ie8: true,
              ascii_only: true,
            },
            compress: {
              pure_funcs: ['makeMap'],
            },
          }).code
        return write(file, minified, true)
      } else {
        return write(file, code)
      }
    })
}

function write(dest, code, zip) {
  return new Promise((resolve, reject) => {
    function report(extra) {
      console.log(
        blue(path.relative(process.cwd(), dest)) +
          ' ' +
          getSize(code) +
          (extra || ''),
      )
      resolve()
    }

    fs.writeFile(dest, code, err => {
      if (err) return reject(err)
      if (zip) {
        zlib.gzip(code, (err, zipped) => {
          if (err) return reject(err)
          report(' (gzipped: ' + getSize(zipped) + ')')
        })
      } else {
        report()
      }
    })
  })
}

function getSize(code) {
  return (code.length / 1024).toFixed(2) + 'kb'
}

function logError(e) {
  console.log(e)
}

function blue(str) {
  return '\x1b[1m\x1b[34m' + str + '\x1b[39m\x1b[22m'
}
